PR middle-end/52691

	* tree-ssa-ccp.c (optimize_stdarg_builtin): Optimize
	__builtin_va_start to __builtin_next_arg if the latter is
	builtin_decl_explicit_p rather than when it is not.

	* gcc.dg/pr52691.c: New test.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@185917 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 24 insertions, 0 deletions

diff --git a/gcc/testsuite/gcc.dg/pr52691.c b/gcc/testsuite/gcc.dg/pr52691.c
new file mode 100644
index 00000000000..7a2d7d8ebb1
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr52691.c
@@ -0,0 +1,24 @@
+/* PR middle-end/52691 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+
+#include <stdarg.h>
+
+int
+foo (int a, ...)
+{
+  int b = 0, c = 0;
+  va_list ap;
+  va_start (ap, a);
+  if (a > 1)
+    b = va_arg (ap, double);
+  if (a > 2)
+    c = va_arg (ap, long long);
+  va_end (ap);
+  return a + b + c;
+}
+
+/* { dg-final { scan-tree-dump "__builtin_next_arg" "optimized" { target { { i?86-*-* x86_64-*-* } && ia32 } } } } */
+/* { dg-final { scan-tree-dump "__builtin_next_arg" "optimized" { target { powerpc*-*-darwin* powerpc*-*-aix* } } } } */
+/* { dg-final { scan-tree-dump "__builtin_next_arg" "optimized" { target { powerpc*-*-linux* && lp64 } } } } */
+/* { dg-final { cleanup-tree-dump "optimized" } } */